Bucket for turbines.



E. H PARQUHAR., BUCKET FOR TURBINES. APPLIOATIDN MLED APR. 7, 190s.

Patented @et 2'?, 1908.

Imvemor.

@y www@ A my UM @ZKM @en/A Witmesses:

' rirrrren offeree EDMUND FARQUHAR, OF SCHENECTADY, NE" YQRK, ASSIGN Olt T0 lE-Nlllll, ELlLClRIC COMPANY, A CORPORATION OF NEW YQRL. i

BUCKET FR TUREINES.

hln. gll. Speeceton of Lettere l'otent. Petented Get. 2f?, 193065. hpplcetion filed April 1, M06. Serial No. Slllflt,

To all whom@ may Concern; to the hase on the othen The motel of Be it known that L Ene/[men En Emmen which the hose is formed should be of .Cinch HAR, e einigen of the Unite' Staten, yee'ning :t charecter that it Will l'loW readily and or Schenectady, County of Seheneemy, ruse with the bucket ends it o relatively Sint@ of New York, have invented Certain low temperature. ln costing the Support co new and useful Improvements 1n Buckets around the bucket ends the buckets are held for Elagtolllnd Turbines, of which the in petition in the mold in euch manner that following ie epeeioefion the proper pitch sind relation between huele The present invention yelteefige venes, ete 1S preserved, as well es the entrance and Oliwls 01' buckets for clasticfluicl turbines, exit ongles eorrectfor the machine for'which 65 end has for its object to improve their con th@ lJUClIGS #1ro intended. Str-notion, v l. may nee my inrention in connection ln carrying ont my invention employ with redini or ariel flow, reaction or iinboekets whioh'ol-e mede of a hotJ Toning pulse machines or o cl'nnhination thereof,

alloy, for exemple, .l prefer to use buckets ln the ease of en miel flow machine the 70 that lere mede by the Sio-called. extrnding buckets occupy radial positions and the process on account of their superior qnalpitch distance between them for a given ties both as to weer and finish and the r-olbucket element is a constant factor. ln the ity with which they may be united to their case ofa, radial flow machine the buckets support. By making buckets of this charYA occupy e position parallel to the :une o' the 75 acter`r each can he formed With smooth, hard turbine und the heee or support 'fused to surfaces and accurately made to the desired the buckets on one end or the other es heet dimensions with the necessary knife-like Sxiits the construction of the machine. The

I edges. Suche bucket will. last for e long pitch distance between hneliets is of course time Without showing the e'tects of the preserved and cleo the :ilinenient circoli 80 action of steam or other elastic fluid thereon, 'erentinlly and laterally.

and is noncorrosive. The bucket-s v are l ncl it desirable to 'Fasten the outer ends smooth and herd when new und under the of the buckets together hy o suitable strip or action 4oli the steam. will retain the smooth cover, which is `pre rehly secured in place :linish and Will not pit' or be otherwise inhy tenons 'formed integral with the ends of e5 jared in service. The buckets are fused 'into the loriclrets opposite Vthe hose or sirpport. a lhase hy pouring molten metal ot e relzr rlhe covcre are provided with openings cor* tively low temperature around the ends responding in shape :incl .size to the tenons, thereof, the Said buckets being placed in e and the letter :we :ilterrfard riveted over suitable mold and so arranges that the ends tf* secure the cover in platee. o()

to be 'fused lproject the required distance into ivly invention is; portienlorly epplicelile l lexit Will not he injured by the heet trene-l ,fitter they are 'pnt :in the molding or in the proper compositions and temperature of which here te he n the space arranged to receive the molten to those machines requiring long huelrets metal. By using en alloy of suitable compo which could not he eetiehictorily ont hy' :i sition and e, metallor the brise o' Support bliclietcntting machine ont of Solid Stoch, of similar character, ind hy vietilel preclint ie e applicable to shorter huclcete. e5

tice that the buckets will he. ,need thereto i By reason of my invention .l ern zihle to f and the sharpened edges et the entrance sind diepenee with machining on the buckets mitted thereto hy the molten motel et the the core Where the letter method oit procedi time the hose or support is formeel. ll here ure is followed. Tvlllwtewer liniehing on the 10o found that en alloy composed of e large prol'iiiclrets is nec-enemy done heitere. ,this per portion of copper and a smaller amount of tienltir-openticir s elter mined Wifh e smell quantity of en By ineens o'l my invention i, ein chie to e loy of copper, nickel end iron 'is Well greatly ileerese the coet ot" mentito/etnie, adapted to produce the desired results. Vfirmly Secure the `hnclrete to their or icc Greetl cere haste he exercised in' ehooeing root, decrease 'the lininhcr el* smell y ts 4 de :ind machined, end

thevinol'ten metal., since otherwise the thm also he is are other sharp edges will he destroyed on one hand elastic hno between hn which :we

or the hnelete'-ryill not he properly united 'free from erfolge-or defereseiehe 'which .'tend to create eddies as'the or construction.

steam flows described l am ablc to dispense with the spaces, resulting 1n loss 1n ettiwires or strips which have heretofore been employed to tie the outer ends of long buckets together, these wires or strips being located at some little distance from the free ends of the buckets. These wires or strips a re objectionable for the reason that they interfere with the free passage of -steam Athrough the bucket spaces and in this manner create eddies resulting' in a decrease in efficiency of the turbine.

In Fig". 4 is shown a bucket'. before it. is fused to its support. Each bucket is provided with a tenon 3 formed integral therewith, but I may omit the tenons on some of the buckets if desired where the latter are short and the strains are not excessive. The. root of the bucket is preferably but not necessarily provided with one or more recesses Sli of suitable shape and size to receive the molten metal at the time the base is cast and form an additional and mechanicalsecuring` means. The recess may be on one or both sides of the bucket or extend completely through itas desired.

Tests have shown that buckets made in accordance with my invention will stand. a st ain of 31,000 pounds without affecting the union between the root of the .bucket and the base. i

A test run of i064 hours was made with buckets made in accordance with my invention, which showed less wear than on those cut from solid steel. in addition to' the i11- ereased life, there is a great decrease in the cost of manufacture over other constructions.

The following' gives a good idea of the properties of the buckets now in commercial prodiuction: elastic limit, 25,000 pounds; tensile strength, '(0,000 pounds; elongation in il, 36 per cent'. reduction of area 50 per cent. The wheel buckets commonly have a through the ciency. fI n 'the accompanying drawing7 which illustrates one embodimentof my invention, Figure l is a view in side elevation of a part of a bucket seg-ment; Fig. Q is a cross-section of the same; Fig. 3 is aslight modification showing a somewhat different form of support; and Fig. 4 is a detail view of a bucket before it is fused to its support.

l represents the base of the bucket segment which may be of any suitable length Ordinarily these segments are made of such a length that they may be conveniently handled, and each is provided with a plurality of' buckets 2 either radially or otherwise disposed and fused thereto. The buckets are made of a hot rolling alloy either by extruding dies or otherwise. They are all nishedto dimensions and surface before they are put in the mold, and the base cast around the ends. The buckets are provided Withtenons 3 of suitable shape and size to secure the cover or shrouding ring` 4t in place. `These buckets may be mounted on the revolving element of the turbine or on a stationary element las desired.

In Fig. 2 is shown a Wheel or carrier 5 adapted to support the base 1 of the buckets. Provision is made in this case for two rows of wheel buckets on each wheel, but the number can be increased or decreased by 'properly modifying the form of the support. In this instance the base is provided With a shoulder 6 that enters a groove in the wheel and the bases are retained by axially extending rivets 8, the rivets passing through the bases on yopposite sides of the wheel so that a single set suffices for-securing two rows. of Awheel buckets.

In Fig. 3 a base l of somewhat different construction is shown. This base is more particularly adapted for the stationary buckets7 but its use is not limited thereto. y In this case, as before, the buckets are of the same construction and-are fused into the base andare provided with a cover t secured in place by tenons 3 havint;` the outer ends thereof riveted over. Where the buckets are long', such as six or eig-ht inches for example, the. cover It not only serves to form one wall of the. tinid spacc7 but'also serves to fasten thc buckets together at their free ends and'form an additional means of support. 'lhe cover and the base are preferably made sonunvhat wider in all cases than the buckets so that; any accidental rubbing will take place thereon instead of on the sharpened edges of the buckets. ly means of the constriu-tion shown l am able t0 provide a bucket'. which can be operated with zgrcatcrclearances than where no cover l slprovidedl. and by arranging; the cover as l second, and the strains thereon dueto centri fugal force are of necessity'high7 hence the limportance of making a secure uniorrwith the support.-

Separately formed buckets have hcret0- fore been secured in place by a calking' strip or strips or-by a ring having slots cnt in one side, the metal between buckets being;l forced into engagement with thc concave and convex walls thereof. objectionable for many reasons, ol which the following arc the principal: 'l`he buckets are held merely by the friction between them and the holdingstrip or ring'. resulting1 in an insecure support. 'l`hc centrifugal strains on these buckets are very great and when one of them lets ,gro it usually results in wrcckinch thc turbine. o r at least injuring" it to such an extent. that it takes a long' time to rcpuir'it, instances are known of itl havinzcr taken weeks to repair a nnu'hinc -al'tcr such an accidmit und put. itin waking condition. Avc'aiu, thc

peripheral speed of from i350 to 450 feet per blur-h arrangements are I rolling alloy, a

some1 cost of the said construction is high and itis a difficult matter to fasten the buckets, or blades as they are sometimes called in place. This difficulty is greatly enhanced where a largernumber of rows are mounted on a coinrnon support such as a revolving drinn `or on the inside of a wheel casing. The character' of the retaining ring` at the base or root of the buckets is such that small crevices are inevitable, and these result in the creation ot' objectionable eddies. it is always a ditlicult inatter to properly aiinc the buckets, and where they are longand the above mentioned arrangements used the ditiiculty is greatly increased.

In accordance with the provisions oi' the patent statutes, I have described the principle of operation ofi niy invention, together with the apparatus which l now consider to represent the best embodiment thereof; but .l desire to have it understood that the apparatus shown is only illustrative and that the invention can be carried out by other means.

What 'I claim as new and desire to secure by Letters Patent of the United States, is,

1. ln an elastic-Huid turbine, the combinag tion of a plurality of buckets made of a het cast-metal support to which the buckets are fused,` and a carrier for the support.

2, lin an elastic-duid turbine, the combina-v tionof a plurality of buckets each having a` concave and a convex Wall and made of a hot rolling alloy, a cast'metal base to which the buckets are fused at one end, a means for connecting the opposite ends of 'the buckets to hold them in alinement and preserve the pitch distance, and a carrier for the base.

ln an elasticfiuid turbine, the combination of a plurality of buckets each being separately formed and provided with concave and convex walls, a base to which the buckets are secured by fusing, tenons on the buckets, a cover or shroud that is secured to the buckets by the tenons, which forms one wall of the Huid passage, preserves the pitch relation between the buckets and assists in securing the buckets against centrifugal' strains, and a carrier for the base.

4. in au elastic-Huid turbine, the combination of' a plurality of buckets each beingl inade of extruded inctai and provided with. a recess at one end, tenons formed integral with the buckets, a cast-metal base to which the buckets are fused, the metal of the base filling' the recesses `and forming an additional. mechanical support, a cover -for the buckets which. is secured thereto by riveting` over the ends oi? the tenons, the said cover acting as a mechanical support to resist centrifugal strains and also to preserve the pitch distance between buckets and hold hein in alinenient against lateral displacenient, and a carrier for the base.

In witness whereof, have hereunto set my .hand this fifth day of April, 1.906.

' v EDMUND H. FARQUHAR. Witnesses f BENJAMIN B. HULL, ALEX. F. MACDONALD. 

